This invention relates to a dosage device having an audible and tactile mechanism that generates variable sliding resistance that may be accompanied by a sound heard by a person to help him or her in the determination of a desired amount of liquid being passed into and from this device. More particularly, the invention relates to a dosage device provided with a resistance and sound generating mechanism accurately indicating an amount of medicine being passed from the medical container to the interior of the dosage device and dispensed from the syringe during the use thereof.
In situations where people have difficulties requiring that they administer certain medicine to themselves there is a persisting problem to accurately transfer the amount of medicine from a container into a syringe and further from the syringe into a body. Such difficulties may include medical problems, such as sight impediments, or body parts not easily accessible or even environmental conditions, for example, darkness. Regardless of these difficulties it is important that the amount of medicine being injected and ejected is accurate.
Another difficulty may arise when a user, typically a construction worker, has to dispense a predetermined amount of medium used for construction purposes in places that are not easily accessible. Similar to difficulties discussed above, the amount of medium to be dispensed has to be accurate.
Attempts have been made in the prior art to overcome these problems and provide some type of structure, which allows a person to accurately transfer the amount of medication to and from a syringe.
The U.S. Pat. No. 4,252,159 to Maki, teaches a dosage device including an elongated slat body on which a syringe is mounted by means of upstanding substantially Y-shaped brackets that are spaced from one another and extending upwardly from a flat exposed surface of the body. An adjustable top member threadedly engages an upstanding internally threaded element provided with externally located lands that, in turn, co-operate with an irregularly shaped knob so as to produce audible signals upon a 360xc2x0 revolution. The engagement and sound between the above-mentioned elements depends upon a number of factors which may include flexibility of the base or play between the threaded engagement such that the outwardly projected portion of the knob may pass over and in engagement with the lands.
The U.S. Pat. No. 4,466,426 to Blackman, discloses a syringe that has a plunger providing an audible sound upon a plunger being withdrawn from the barrel of a syringe.
The U.S. Pat. No. 4,883,101 to Strong, discloses a device for filling an injection syringe which incorporates a sound indicator provided with mechanical, electrical or an electronic sound device. A spring-loaded ball bearing is biased against a gear wheel and produces a distinctly audible clicking sound when the gear moves a single notch. A user counts the sounds accurately indicating the amount of liquid medicine drawn into the syringe when the attached syringe holder moves.
The U.S. Pat. Nos. 5,741,232 and 5,795,333 to Reilly, disclose a front loading syringe having a movable plunger rotatably on an injector housing. An audible indicating mechanism is activated when the syringe is essentially in the desired mounted position and includes ribs which are function as volumetric gradations.
While the above noted patents are all directed to structures which attempt to overcome problems associated with dispensing proper dosage of medicine, these structure are rather complicated and inconvenient in use. The need therefore arises to have a simple structure of a dosing device that will allow a user to administer medicine in a simple and efficient manner.
With a device according to the invention one can operate a dosage device, such as a syringe filling assembly, in a conventional manner and still be able to correctly meter dosage amount.
Particularly, the syringe filling assembly in accordance with the invention has a means capable of generating an audible sound as a plunger moves relative to a barrel.
According to one aspect of the invention, the barrel has an inwardly extending formation periodically engaging recesses that are formed in the plunger. The spacing between the recesses is uniform and is dimensioned such that one recess passing by the formation will allow the withdrawal of the plunger to a point at which one volume unit is directed into or out of the dosage device.
In accordance with another aspect of the invention, the barrel is formed with a plurality of formations engageable by an outwardly extending formation that is mounted to the plunger and is shaped to produce an audible sound.
Still another aspect of the present invention is to provide a holder removably mounted on a proximal end of the barrel and having a formation that engages a plurality of the recesses formed on the plunger.
It is therefore an object of the invention to provide a dosage device having a simple structure reliably indicating proper dosage amount.
Still another object of the invention is to provide a dosage device having a structure capable of producing an audible sound corresponding to predetermined dosage amounts entering or leaving the dosage device.
Yet another object of the invention is to provide a dosage device having a barrel with a formation extending toward and periodically engaging a plurality of recesses that are formed on a plunger of the dosage device.
Another object of the invention is to provide a dosage device having a plunger, which is formed with a formation extending toward and periodically engaging a plurality of recesses formed on a barrel of the dosage device.
Yet another object of the present invention is to provide a dosage device having a handle removably mounted to a barrel and formed with a formation that extends toward and periodically engages a plurality of recesses formed on a plunger of the dosage device.